A real-time PCR assay for the detection the frequency of imazalil-resistant Penicillium digitatum
Chen GJ, Zhang AF, Jiang LY, Xu SF, Ma ZH and Li HY
Program and Abstracts, 11th International Citrus Congress (ISC Congress), 26-20 October 2008, Wuhan, China. 333 pages.
2008
บทคัดย่อ
A real-time PCR assay for the detection the frequency of imazalil-resistant Penicillium digitatum
Citrus green mold caused by Penicillium digitatum (pers) Sacc. is the most destructive disease of postharvest citrus. To control this disease, imazalil, belonging to one of fungicides in 14-α-demythlation inhibitors (DMIs), is commonly used since early 1980s. Since the extensive and sequential using, imazalil-resistant P. digitatum was first reported in USA, subsequently in European and China. The potential impact of imazalil-resistant biotype on postharvest decay control was demonstrated in many commercial packinghouses. Monitoring the frequency of imazalil-resistant P. digitatum in a packinghouse would be a step to ensure the control of green mold. To date, two molecular mechanisms (insert of a 504 bp and 199 bp in promoter region of CYP51 gene, respectively) were demonstrated to be response for the formation of imazalil-resistance. Based on these mechanisms, two pieces of forward primers specific to resistant type I (504 bp insert) and type II (199 bp insert) were designed, respectively. Combining with a common reverse primer, a method of real-time PCR assessment was subsequently developed to quantify the frequency of imazalil-resistant P. digitatum (FR) in one reaction for a multiple samples collected from a packinghouse. This method was demonstrated to be as accurate as conventional PCR, but have the advantage of high throughput, time and labor-saving.